Floating oil confining apparatus

ABSTRACT

Apparatus for collecting oil from the surface of a body of water having two V-shaped assemblies of flexible inflated floats, one arranged 5 to 25 feet leewardly of the other on the same central axis, whereby the wind and current drive the oil into the open end of the assemblies and cause it to be funneled rearwardly to their apices. Each V-shaped assembly is provided with a depending skirt of impermeable sheet material, the lower edges of the skirts at either side of the inner assembly being interconnected by shock cords and the lower edges of the skirts on the outer assembly being connected to the inner assembly by netting.

White @tntes Patent m1 menses (72} Inventors Hugh J. Fitzgemld Austin;Ernw ll. lfioe pll, Define, both of, Ten. [21] Appl. No. 882,638 [22]Filed Dec. 5, 1969 [45] Patented July 6, 11971 [73] Assignee (I eennPollutio Cotml, line.

Dulles, Tex.

{54] FLUATKNG Olll. CONFINING APPARATUS w Clninm 3 Drawing mm.

[52] 1.1.5. Cl. 61/1, 6l/5,2l0/242 {51] lnt.Cl ..B0ld 21/02, EOZb 15/04[50] Field ollsenreh 6l/l,5; 210/242 [56] References Cited UNlTED STATESPATENTS 3,476,246 I 1/1969 Dahan 6l/l 3,503,214 3/l970 Desty et al. A.61/1 FOREIGN PATENTS 1,528,855 1968 France 61/1 Primary Examiner-JacobShapiro Attorney-Richards, Harris & Hubbard AESTRACT: Apparatus forcollecting oil from the surface of a body of water having two V-shapedassemblies of flexible inflated floats, one arranged 5 to 25 feetleewardly of the other on the same central axis, whereby the wind andcurrent drive the oil into the open end of the assemblies and cause itto be funneled rearwardly to their apices. Each V-shaped assembly isprovided with a depending skirt of impermeable sheet material, the loweredges of the skirts at either side of the inner assembly beinginterconnected by shock cords and the lower edges of the skirts on theouter assembly being con nected to the inner assembly by netting.

FLOATING OIL CONFIINING APPARATUS This invention relates to apparatusfor confining an oily material on the surface of a body of water andremoving the resulting accumulation.

It is well known that when oil is released in or on a large body ofwater, because of the immiscibility of oil with water and the fact thatoil is lighter than water, the oil rises to the surface of the water inthe form of a film or slick which spreads to cover a large area andwhich is capable of migrating considerable distances depending upon thewind and the current. Where large quantities of oil are released, forexample due to the sinking or damage of an oil tanker or to escape ofoil under pressure through a fissure in an otherwise impermeableformation overlying an oil reservoir or in connection with an offshoredrilling operation, movement of the oil slick to adjacent coastal areascan not only form an unsightly and messy residue on beaches, interferingwith their recreational uses, but also have serious effects on aquaticbirds, fish and other marine life, as well as other adverse ecologicalconsequences.

Until recently there has been no effective means for confining and/orremoving large oil films from open bodies of water. Attempts to usedetergents and other chemicals to emulsify and/or disperse the oil havefor the most part proven ineffective. On the other hand, attempts to usedetergents and other chemicals to emulsify and/or disperse the oil havefor the most part proven ineffective. On the other hand, attempts toconfine the oil to a limited area to prevent its dispersion, for exampleby a chain of logs or elongated floats connected end to end in a circle,or to skim the oil from the surface by towing means such as a chain offloats between a pair of tugboats moving on parallel courses, haveproved virtually worthless due to the fact that the surface of an ocean,bay or large inland lake is almost invariably subject to waves orchoppiness which causes the oil film to be washed over the tops of therigid floats so that most of the oil escapes.

In the copending application Ser. No. 836,545 filed June 25, 1969, thereis disclosed an apparatus for confining an oily material to a limitedarea of the surface of the water, thereby preventing its spreading ormigration, and for removing the resulting accumulation. In oneillustrative form, that apparatus comprised a series of elongatedflexible, hollow, tubular float members, which were inflated to lowpressure, on the order of 0.5 p.s.i., to maintain a high degree offlexibility, and which were connected end to end in a ring whichsurrounded an area of substantial width around the source of the oilymaterial. Depending from the float members were skirts of impenneablesheet material weighted at the lower ends, for example by a chain, andextending downwardly a distance exceeding the anticipated maximumthickness of the oily accumulation. The ring was generally rhomboidal inshape, with each corner on the windward side connected to an anchormeans to keep the ring spread and to prevent its drifting due to windand current. The flexibility of the ring allowed it to conform to thewave motion and chop of the surface and thus tended to prevent escape ofthe oily accumulation either over the tops of the float members or underthe bottom of the skirt. A transfer pipe was supported within the ring,preferably at the leeward comer, with the inlet end of the pipe at alevel within the thickness of the oily accumulation. The pipe extendedto a pump, for example on a storage barge anchored adjacent but outsidethe ring, to remove the oily material as it accumulated.

Tests of that apparatus indicated that it did a highly creditable job ofconfining the oil under most surface conditions, substantially betterthan any previously known device. However, in heavy seas or extremechoppiness, a portion of the oil inevitably washed over the tops of thefloat members and escaped. However, a most interesting phenomenon wasobserved: Although the barrier extends for only a few feet and above andbelow the surface, it unexpectedly produced a marked effect in calmingthe surface motion, creating an area of dead water" on the leewardsideof the barrier. Thus it was assumed that a second, similar barrier onthe leeward side of the first, within this dead water area, mightperform much more efficiently than the first barrier and capturesubstantially all of any oil escaping from the first. Tests fullyconfirmed this assumption.

The present invention exploits this phenomenon by providing twogenerally V-shaped float assemblies, each formed of a series ofinflated, tubular float members connected end to end, with one assemblypositioned a short distance behind the other along the same centralaxis, with anchor means to hold the divergent ends of the assemblies inposition to windward, with their apices trailing leewardly so that theoil is driven into the open end of the assemblies and funneled towardtheir apices. At least the outer one of the two assemblies is providedwith a depending skirt which extends several feet below the surface withits lower end preferably connected to the inner assembly by tie means,such as netting, to prevent the skirt from streaming leewardly andallowing the oil to escape beneath it. The apex of the outer assembly isconnected to a sump which trails rearwardly thereof and in which the oilis collected for removal, for example through a flexible line connectedto a pump on a nearby barge.

In the drawings:

FIG. l is a diagrammatic plan view of an illustrative apparatusembodying features of the invention.

FIG. 2 and 3 are enlarged fragmentary sectional views taken respectivelyon the lines 2-2 and 3-3 of FIG. 1.

As best shown in FIG. l, the illustrative apparatus comprises twogenerally similar V-shaped float assemblies 10 and 12, each formed of aseries of inflated, elongated, tubular float members ll4l connected endto end. The two float assemblies are spaced a short distance apart alonga common central axis, with the divergent ends of the two assembliessecured by lines ll5 to anchor means, for example anchors 118 or othermoorings, such as pilings or slow-moving tugboats, etc., which keep theopen ends of the two assemblies facing to windward with their apices 20trailing leewardly.

As may be seen in FIGS. 2 and 3, each of the float members M may beformed of four quadrantial segments 16, each of which extends lengthwiseof the elongated tubular member around one-quarter of its circumference.The segments are formed of flexible, impermeable sheet. material, suchas nylon fabric or other strong textile material, impregnated with orlaminated to neoprene, rubber or similar flexible plastic material. Theproximate ends of the adjacent segments are adjoined by marginalportions which are bonded face to face, for example by cementing, heatsealing or vulcanization, to form radially outwardly extending flangesM. These flanges 24 are provided with holes-preferably reinforced, forexample by grommets 2r6-for convenience in attaching the float membersto one another and to ancillary parts of the apparatus. The upperflanges 24 increase the effective height of the barrier.

The lower flange 24 preferably encloses an integral cable or rope 2!formed, for example of nylon or similar material, which is provided ateach end with a projecting loop or other means of attaching the floatmembers together and for transmitting the tensile forces, imposed eitherby wave action or by towing to or from the point of use, withoutstraining and possibly tearing the float members.

Attached to the bottom edge of the lower flange 24, for example bylacing a line 28 through their aligned grommets 26, is a depending skirt349 which is formed of a flexible, impermeable sheet material, forexample the same type of material used in fabricating the float members,although possibly of lighter gauge. Secured adjacent the lower edge ofthe skirt 30 is a chain 32 which weights the edge of the skirt to insurethat it extends downwardly into the water, without impairing itsflexibility. The width of the skirt exceeds the anticipated maximumthickness of the oily accumulation to prevent the oily material fromescaping beneath the bottom edge of the skirt. The skirt 30 may suitablybe made integral with the float member 110, for example by merelyextending the marginal portion of one of the lower segments 116.However, forming it of a separate sheet, removably attached to the floatmember, as shown, allows it to be replaced readily in the event ofdamage, or in the event a deeper skirt is desired, for example toaccommodate unusually heavy oil accumulations.

The lower edges of the skirts 30 at opposite sides of the inner V-shapedassembly 110 are interconnected by tie means such as heavy elastic shockcords 34 Which, as shown in FIGv I, extend transversely between the twolegs of the assembly at spaced positions therealong, with their endsconnected to bridles 35 of netting to distribute the stress along theskirts 30 This limits outward movement of the skirts 3t) and preventstheir trailing rearwardly due to the pressure imposed upon them by thecurrent, and thus allowing the accumulated oily material near thesurface to escape beneath them. The elasticity of the shock cords 34 andof the netting bridles 35 limits the stress imposed on the skirtsdfl inheavy seas.

The lower edges of the skirts 30 on the outer V-shaped assembly 12 aresimilarly secured to retaining means, such as the netting 36 whichextends inwardly beneath the surface and it connnected to the lowerflange 2 of the float members 14 of the inner assembly it). The loweredges of the skirts 30 at each side of the outer assembly 112 adjacentits apex, and rearwardly of the apex of the inner assembly Ml areinterconnected by an additional triangular section of netting 38.

The apparatus thus includes generally similar inner and outer V-shapedbarriers oriented so that the wind and current will drive the oilymaterial 0 into the open end of the inner barrier. The float members,being inflated to only a relatively low pressure, such as 0.5 p.s.i.g.,are extremely flexible and can readily conform to undulations of thesurface. The barriers extend above and below the surface a sufficientdistance to prevent escape of the oily material it, which is thereforefunneed inwardly and rearwardly toward the apex of the inner assembly.The two legs of each of the V-shaped assemblies are preferably arrangedto subtend a relatively shallow angle at the apex, so that the wavemotion is generally parallel to the legs, thus limiting the forceimposed upon them and reducing the tendency of the waves to break overthe top of the barriers and instead channelling the waves along thebarriers to the apex. The oily material which reaches the apex of theinner assembly passes rearwardly through a large, flexible pipe 410 ofreinforced neoprene or similar material which is positioned with itsforward or inlet end at the apex and which trails rearwardly with itsoutlet end beneath a flexible triangular cover 42 which extends over theapex portion of the outer assembly 12. As best shown in H6. 3, the outerassembly 12 may be built up in height adjacent its apex by lashingtogether three float members Ml in a pyramid arrangement, by lacingropes 43 through their aligned grommets 26. The trailing edges of thecover 42 are lashed to the upper flange of the top float member 114 byropes 85, while its leading edge is supported above the surface of thewater on a series of float members 44 (FIG. 11). This insures that allof the oily material reaching the apex of the outer assembly 12 willpass beneath the leading edge of the cover 42 and be funneled into theinput end of a flexible pipe 4/6 which extends from the apex into afloating sump 48 which trails leewardly thereof with ropes 419 interconnecting the float members i l at the apex of the outer assembly 12 withthe sump 43 to limit the stress on the pipe as. The sump 48 is coveredboth top and bottom by flexible sheet material 50 and is surrounded byan inflated float ring 52 which supports it at the surface. The top andbottom covers of the sump 48 are formed with considerable fullness orexcess material to permit them to bulge outwardly as oily material flowsinto the sump through the pipe 46. The sump 48 thus has substantialstorage capacity. The oily material is removed from the sump 4 8 througha flexible conduit 54 which is connected to a pump on a barge (notshown). As the sump 4-3 is emptied, the upper and lower covers collapsetogether.

Due to the fact that the outer assembly 12 is in the dead water "area toleeward of the inner assembly it), it does anextremely efflcient job ofcapturing any oily material which escapes from the inner assembly inheavy seas or extreme turbulence. A spacing of approximately 5 to 25feet between the two assemblies is preferable, depending upon surfaceconditions.

To maintain the spacing of the two assemblies and prevent their movingtoo close together and acting effectively as only a single barrier, aseries of lightweight but relatively rigid tubular members 56 made, forexample, of stiffly flexible plastic pipe, may be connected between theinner and outer assemblies at various oblique angles. As shown in FIG.2, the ends of the tubular members 56 may be lashed to the grommets 260f the side flanges 24 of the float members 14. These spaces member 56are used sparingly, and only if they prove necessary under the surfaceconditions being encountered, because it is highly desirable to preservemaximum overall flexibility in the apparatus, thus allowing it toconform readily to the constantly fluctuating surface as well asavoiding localized stresses associated with rigid members.

As will be appreciated, this entire apparatus may be quickly assembledand disassembled. The float members 14, when deflated and. flattened,may be coiled on a reel, in the manner of a flrehose. The skirt panels30 and netting panels 36 and 38 may be folded flat and coiled on aroller. Thus the apparatus may be stored conveniently and transportedeasily to various locations, as required, and quickly assembled in situ.Alternatively, it may be fully assembled, except for the spacer members56, at a shore installation and towed to the desired location with allfour legs of the two V-shaped assemblies folded together to form asingle narrow, elongated bundle, thus reducing the drag on the towingvessel and minimizing the strain on the apparatus.

The apparatus is positioned leewardly of the source of the oil. As windconditions and current change, the assembly will weather cockautomatically to the optimum orientation, if the wind and current shiftso that the two legs of the V-shaped assemblies move too closelytogether or so that their open ends are no longer directed toward theoil source, the anchors or moorings 18 are shifted to restore thedivergent relation of the legs and their proper orientation relative tothe source. The open end of the inner V-shaped assembly provides freeaccess by work boats for inspecting and servicing the apparatus.

We claim:

1. Apparatus for confining and removing oily material from the surfaceof a body of water comprising a series of inflated, flexible, tubularfloat members connected end to end to form two V-shaped assemblies, tiemeans connecting said two V- shaped assemblies to keep them aligned, onedirectly behind the other along the same central axis and spaced apart adistance of approximately 5 to 25 feet, anchor means secured to thedivergent ends of said V-shaped assemblies to held said assemblies inposition with their apices trailing leewardly thereof, whereby said oilymaterial is driven by the wind and/or current toward said apices, skirtmembers depending from at least the outer one of said V-shapedassemblies and projecting below the surface of the water, retainingmeans secured adjacent the lower edge of said skirt members to keep themprojecting generally downwardly and prevent their streaming rearwardlyand thus allowing escape of said oily material beneath them, conduitmeans adjacent the apex of at least the outer V-shpaed assembly forremoval of the accumulated oily material.

2. Apparatus as described in claim 1 in which said retaining meanscomprises tie members extending forwardly and inwardly beneath the waterand attached to the inner one of said V-shaped assemblies.

3. Apparatus as described in claim 2 in which said tie members comprisesections of netting.

4. Apparatus as described in claim 11 which said anchor means comprisesanchors resting on the bottom of said body of water and secured by linesto the divergent open ends of the inner one of said V-shaped assemblies.

5. Apparatus as described in claim 1 in which said tie means includesresilient structural members extending between said two Vlshapedassemblies at varying oblique angles to keep them normally spaced andapart the desired uniform distance.

6. Apparatus as described in claim 1 in which the outer one of saidV-shaped assemblies is built up in height adjacent its apex by lashingtogether several of said tubular float members in a pyramid arrangement.

7. Apparatus as described in claim 6 in which a cover member ofimpermeable sheet material extends over the apex of the outer one ofsaid V-shaped assemblies, with float means at the leading edge of saidcover to keep it spaced above the surface.

8. Apparatus as described in claim 7 in which a flexible pipe extendsfrom the apex of the inner one of said V-shaped assemblies leewardly toa position beneath said cover.

9. Apparatus as described in claim 1 which includes a sump trailingrearwardly of the apex of the outer one of said V- shaped assemblies andconnected thereto by said conduit means.

10. Apparatus as described in claim 9 in which said sump is supportedwithin inflated float means is enclosed by top and bottom covers offlexible sheet material which are formed with fullness whereby theybulge outwardly as oily material flows into the sump through saidconduit means and collapse inwardly as oily material is removed fromsaid sump.

2. Apparatus as described in claim 1 in which said retaining meanscomprises tie members extending forwardly and inwardly beneath the waterand attached to the inner one of said V-shaped assemblies.
 3. Apparatusas described in claim 2 in which said tie members comprise sections ofnetting.
 4. Apparatus as described in claim 1 which said anchor meanscomprises anchors resting on the bottom of said body of water andsecured by lines to the divergent open ends of the inner one of saidV-shaped assemblies.
 5. Apparatus as described in claim 1 in which saidtie means includes resilient structural members extending between saidtwo V-shaped assemblies at varying oblique angles to keep them normallyspaced and apart the desired uniform distance.
 6. Apparatus as describedin claim 1 in which the outer one of said V-shaped assemblies is builtup in height adjacent its apex by lashing together several of saidtubular float members in a pyramid arrangement.
 7. Apparatus asdescribed in claim 6 in which a cover member of impermeable sheetmaterial extends over the apex of the outer one of said V-shapedassemblies, with float means at the leading edge of said cover to keepit spaced above the surface.
 8. Apparatus as described in claim 7 inwhich a flexible pipe extends from the apex of the inner one of saidV-shaped assemblies leewardly to a position beneath said cover. 9.Apparatus as described in claim 1 which includes a sump trailingrearwardly of the apex of the outer one of said V-shaped assemblies andconnected thereto by said conduit means.
 10. Apparatus as described inclaim 9 in which said sump is supported within inflated float means isenclosed by top and bottom covers of flexible sheet material which areformed with fullness whereby they bulge outwardly as oily material flowsinto the sump through said conduit means and collapse inwardly as oilymaterial is removed from said sump.